Holding this black crystal flying sword in his hand, Yun Zhan felt that it was as light as nothing, only a foot long, no more than half a finger wide, small and thin, and the blades on both sides were as thin as cicada wings, revealing a dazzling cold light.

"Bell!—"

Yun Zhanyi exuded his spiritual power and attached himself to the Black Crystal Flying Sword, wanting to sacrifice it, but it was only slightly raised, and then fell back into his palm.

"Condensing the sword pattern just now, my spiritual power will be consumed!" Yun Zhan said secretly, and estimated: "However, with my current spiritual power, if I fully recover, I can only control this Black Crystal Flying Sword at most, and if I use it around me, I can only have a range of 100 steps at most, and if I exceed it, I will lose control!"

Within a hundred steps, one step is at most half a meter, that is to say, Yun Zhan can control this Black Crystal Flying Sword at this time, and he can use it freely within fifty meters at most, if the distance is widened, the spiritual power will be unsustainable, and the Black Crystal Flying Sword will be like a kite with a broken string.

"Compared with the real flying sword, this black crystal flying sword has not only greatly shrunk in size, but also greatly reduced its power, and I have a lot of restrictions on how to use it, strictly speaking, this is not a real sword mastery, it can only be regarded as a surprise hole card, if you don't move, once you use it, you must defeat the enemy to win!" Yun Zhan stroked the sword body and sighed secretly.

If you want to divide the spiritual power, then in the entire Black Rock City, Xu Hao should be regarded as the strongest in the spiritual power, and he has already reached the level of substance, while Yun Zhan's spiritual power is still in the stage of transforming from virtual to real at this time.

According to the experience of Yun Zhan's previous life, if you want to really reach this level, you need to at least upgrade from the Dao Fetal Realm to the Yuan Infant Realm, and you have to go through a calamity.

Therefore, with Yun Zhan's current spiritual power, this Black Crystal Flying Sword is like a dementor eye, and can only be used as one of the few hole cards.

After putting away the Black Crystal Flying Sword, Yun Zhan put the remaining half of the Black Stone Crystal into his arms, although now he can only control a Black Crystal Flying Sword, but after his spiritual power is improved, he can also refine another Black Crystal Flying Sword, as the number of flying swords increases, Yun Zhan may try to arrange a simple jianzhen.

"Here!" After seeing that Yun Zhan was all right, Xu Hao handed over a jade box to Yun Zhan, and said with a lot of pain: "This is a second-grade heaven and earth elixir - Seven Star Grass, which can allow you to quickly recover the lost spiritual power, and after nightfall, the power of the Blood Soul Trapping Demon Array is the strongest, and when it is midnight, we will start replacing the soul stone!"

"Uh!" Yun Zhan was stunned, he originally wanted to delay ** and come back to help him tomorrow, but he didn't want Xu Hao to be so anxious, so he didn't hesitate to consume a heaven and earth elixir, and he also wanted to complete the replacement of the soul stone array eye tonight, which shows how important this matter is to Xu Hao.

The general heaven and earth elixir is just to repair injuries, or increase the strength of the sword qi and physical body, but there are very few that can restore spiritual power, and the price is naturally higher.

Yun Zhan opened the jade box and took the seven-star grass in the box, and immediately felt that the spiritual power that had been squandered began to recover rapidly, and when it came to midnight, he would definitely be able to return to his peak state.

"While there is still some time, let me explain it to you!" Xu Hao saw that it was still early, so he began to introduce the situation at the bottom of the Sword Casting Tower to Yun Zhan, as well as the specific control method of the Blood Soul Trapped Demon Array.

Xu Hao's explanation was extremely detailed, and he explained every detail clearly, lest there would be any omissions, and he didn't finish until midnight.

"Bang!-"

Seeing that the time had come, Xu Hao's heart moved, took out a huge soul stone from the Qiankun ring, and said to Yun Zhan: "You go down first, and when you completely control the big array, then knock on the tower wall three times, and I will start to replace the formation eye, this process will take about half an hour, during this period, no matter what happens, you must control the big array, and you must not let that one break free!"

Yun Zhan nodded, and began to walk down the stairs towards the bottom of the tower.

According to Xu Hao, this sword-casting tower is divided into two layers, the upper layer is more than ten zhang high, and the part that goes deep into the ground is more than 100 zhang deep, this is to allow the blood soul to trap the demon array, which can absorb the earth qi through the underground, so as to exert greater power.

Yun Zhan walked all the way down the stairs for more than ten minutes, but found that although he went deep into the ground, there was no darkness at all, but the light became more and more abundant, and when he went deep into the bottom of the tower, it was like day.

The area at the bottom of this tower is huge, it looks like it is thousands of square meters, it is boxy, and the ground is paved with an unknown metal, like a soul stone, and at the same time carved with countless grooves, forming intricate patterns.

Yun Zhan looked around and found that these patterns were divided into a total of twelve, some resembled galloping horses, some resembled poisonous snakes coiled together, and some resembled vicious dogs that barked wildly......

These twelve patterns, none of them are the same, coiled in a circle, forming a circle, and in the middle of this circle, a fist-sized ball is quietly suspended, the whole body is fiery red, constantly scattering dazzling firelight.

"Squeak!" seemed to feel the fire, Ahri, who was originally asleep in Yun Zhan's arms, suddenly got out of his head, and his big black jewel-like eyes looked straight at the fiery red ball.

Ahri's eyes were shining with green light, and it seemed that the ball had a strong ** on it, making the little guy's mouth continue to drool.

"No!" Seeing that Ahri wanted to get out and run towards the ball that was constantly emitting firelight, Yun Zhan hurriedly pressed it back, shook his head and said, "Don't run around, it's full of dangers here!"

"Squeak......" Ahri struggled as she pointed to the ball.

It took a long time for Yun Zhan to understand what Ahri meant, and he was shocked, "What! You actually ate the flames emitted by that ball!?"

"Squeak!" Ahri nodded, and told Yun Zhan that it had come to the bottom of the sword-forging tower by mistake before, and had devoured the flames emitted by the orb once, and the flames were not only delicious but also helped it increase its strength.

It's a pity that Xu Hao noticed it, and sent a double-headed eagle to guard the sword-casting tower, Ahri wanted to sneak in again many times in a row, but unfortunately he was discovered by the double-headed eagle, and a few days ago he wanted to sneak in, but he was injured by the double-headed eagle, but fortunately he was rescued by Yun Zhan.

"That's not going to work!" Even if Ahri had experience, Yun Zhan refused to agree, and secretly guarded: "There is an extremely frightening existence suppressed here, and if there is a slight mistake, the two of us will be miserable!"